Engine governor



Nov. 18, 1947. M. MALLORY ENGINE GOVERNR Filed Nov. 9, i944 I N v E NTO R Nar/0n /Va//o/y Patented Nov. 18V, 11947 UNITED STATES PATENT GFFICE ENGINE .GOVERNQ Marion Mallory, Detroit, Mich. Application November 9, 1.944. serai NQ. 562.711 2 Claims. (c1. 12s-103) This invention relates to a governor for controlling the speed of an internal combustion engine and more particularly to an engine speed governor which is actuated by changes in the intake passageway pressure.

One of the main difficulties with present day governors for internal combustion engines is that they have a tendency to cause or permit considerable surging in the speed of the yengine'as the load condition varies even when the load is well within the power developed by the engine.

This invention contemplates an engine governor which will control the speed of an internal combustion engine at any predetermined desired speed with greater precision and nicety than heretofore possible.

In the drawing:

Fig. 1 is an elevation partly in section showing my speed governor assembly.

Fig, 2 is afragmentary detail sectional View showing the centrifugal air bleed valve open, and Fig. 3 shows the same closed` The parts of my invention are referenced as follows: engine I, intake passageway 2, air inlet opening 3, governor valve 4 of the butterfly type, governor valve shaft 5, tension spring 6 connected to arm 'I which is fixed on the valve shaft `5, suction device 8, suction chamber 9, flexible diaphragm I0, rod II connecting diaphragm I with arm l, conduit I2 connected at one end with conduit I3 which leads to suction chamber 9 and to conduit i4 which communicates with the intake passageway through orifice l on the atmosphere side of governor valve 4 and with the intake passageway on the engine side of governor valve 4 through orice I6. The other end of conduit I 2 communicates with the interior of ignition distributor housing Il through passageway I8 which continuously communicates with passageway I9 in the distributor shaft which leads to cylinder 2U in rotary valve housing 2| xed on the distributor shaft I9. Cylinder 29 is air bled through oriiice 22 to the inside of distributor housing `II which communicates with atmosphere through port 23. Orifice 22 is controlled by centrifugally unbalanced valve 24 connected to tension spring 25 which tends at all times to hold valve 24 open. Valve 24 is provided with a cylindrical axial projection 26 having a smaller diameter than orce 23. Projection 26 moves back and forth in orilice 22 but never pulls completely out of orilice 22. Projection 25 is connected to a conical valve portion 2l which is arranged to seat against a conical valve seat 28 adjoining orilice 22. Conical valve portion 21 and conical valve seat 2B are preferably of the same size.

The main body 29 of valve 24 operates as a piston in cylinder 29 and has a diameter and cross sectional area considerably, or several times greater than the cross sectional area or diameter of -either valve 2'I or orifice 22. Obviously, there must be some air bleedV from orifice 22 to passagevvay I9. For descriptive purposes this air bleed takes the formof one or more grooves shown at 30 in the' outer face of valve body 29. The air flows from orice "22 vthrough grooves 3l) into passageway I9. Grooves 30 restrict the iiow from orifice to passageway I9 so that when the engine is running and valve 24 is open there will be a lower pressure inthe space 3| in back of piston 24 than in thespace 32 in front or on the air inlet prince side of valve l24.

The operation of my device is as follows: Let us assume that the manually controlled carburetor throttle valve 3 3 is wide open and the governor is controlling the vspeed of the engine. The distributor shaft I9 and valve housing 2l will rotate in accordance with engine speed and when the engine reaches its governed speed, valve 24, being centrifugaily unbalanced, will tend to close 0.1' momentarily C195@ Qre 22- As valve 24 m0- mentarily closes oriiice 2 2 the vacuum existing in the intake passageway at orifice I6 tends to establish itself in suction chamber 9, thereby moving g0vel-nor valve 4 toward closed position to throttle the charge ilowing into the engine. As valve 4 moves toward closed position orifice I5 tends to actl as an air bleed to orice L6 and as valve 4 tends to move toward open position orifice I4 ceases to be an air bleed and eventually becomes a suction orice, as described in my copending parent application Serial No. 466,961, filed November 25, 1942, now Patent Number 2,881,550.-

I-t should Vbe noted that as valve 24 tends to close orifice 22, the closing of the valve is opposed by the intake passageway vacuum and also by tension spring 25. As valve 24 momentarily closes three different pressure conditions are influencing valve 24; namely, atmospheric pressure at orifice 22, the intake passageway vacuum or pressure in chamber 3I, and a higher but subatmospheric pressure obtaining in chamber 32 between the Yfront face of valve v24 and oriiice 22. When valve 24 momentarily closes a pressure equal to the difference between the subatmospheric pressure in space `3 2 ,and atmospheric pressure is acting over an area equal to the area of orifice 242' and'tending to open valve 24. The area of orifice 22, however, is small in comparison with the cross sectional area of piston valve 24 so that it is the minor force o r power opposing the closing of valve 24. Ihe `pressure Vdifference which exists between the low vacuum in chamber 3 2 and the higher vacuum in chamber 3| acts over the cross sectional area of piston 2,4 and is the major force Vopposing the closing of valve24. It is the vacuum behind Valve 24 in chamber 3i which is the real or `major power which opposes closing of the valve. 'This vacuum or suction in chamber 3l is supplemented by the velocity or kinetic energy effect of the air flowing through oriiice 22 and through the clearance between valve body 29 and cylinder 20 which, for descriptive purposes, is shown as groove 30. It is these forces which play upon and influence the action of valve 24, that stabilize the action of the valve and prevent surging of the engine speed. As a matter of fact, the centrifugally unbalanced valve, above described, acts as a robot mind inuencing the suction device 8 to move valve 4 toward open position in response to increased loading of the engine and to move valve 4 toward closed position in response to decreased loading of the engine so that the governed speed of the engine remains remarkably uniform, free from any substantial surging as long as the engine is not required to pull a load greater than the maximum power developed by the engine. When the engine is being accelerated from idle speed to its governed speed, valve 24 remains open and there is little or no vacuum in chambers 3l or 32 because as long as valve 24 is open the governor valve 4 will be open and there will be little suction in the conduit I2, but as soon as the engine reaches its governed speed, the centrifugal force will cause valve 24 to momentarily close against seat 28. The suction chamber will then be subject to the suction created by the velocity of the charge flowing by orices I5 and I6. This suction will be high enough to start valve 4 towards a closed position, but as valve 4 moves towards a closed position the suction will rapidly increase at orice IE causing valve 4 to completely close. The vacuum in conduit I2 and suction device will rise very high momentarily but this excessive vacuum in chamber 3l behind valve 24 will move the valve 24 slightly away from seat 28 to prevent the valve 4 from remaining completely closed which would slow the engine down almost to an idle speed.

The action of the pressure on valve 24 is very important, for example, supposing the spring 25 in the rotating valve was set to give an engine speed of 2500 R. P. M., the valve would be slightly away from seat 28 which would air bleed the suction device enough to cause valve 4 to b-e open enough to permit enough charge to flow so the engine will run 2500 R. P. M. If a stop was put on throttle 4 so it could not close any further than this and the throttlevalve 33 was suddenly opened from idle, the engine perhaps would go far beyond 2500 R. P. M., perhaps 3000 or 3200 R. P. M. Of course, it would settle back to 2500 R. P. M. but this overrun would be veryundesirable. The overrun is eliminated by closing valve 4 almost completely which cuts off practically all of the charge momentarily.

When the engine is being accelerated with throttle 33 wide open from idle position'tc the governor cut-off speed, valve 24 is completely closed against seat 28. The velocity by orifices I5 and I6 is enough to start valve 4 towards a closed position, then there is a rapid increase of vacuum at orice I6 which suddenly increases the vacuum to a point that momentarily closes valve 4 almost completely, so much so that the charge is restricted to not much more than enough to idle the engine but this highvacuum in chamber 3l behind valve 24 nulliiies the centrifugal force and moves valve 24 slightly away from seat V28, admitting enough air bleed to suction device 8 so that valve 4 will open far enough to give the engine the 2,500 or whatever the governed cut-off speed is.

If i1; were not for the vacuum behind the large area of valve 24, the centrifugal force would hold valve 24 against seat 28 and if the engine had a cut-off speed of 2500 R. P. M., it w-ould perhaps sink to 2000 R. P. M. or until such time as the power of centrifugal force reduced to a point to cause valve 24 to move away from seal, 28. rihe engine would constantly surge from 2000 to 2500 R. P. M. Further, the time of loading would depend entirely on centrifugal speed means which would mean there would be a variation 0r time element of 300 to 500 revolutions between wide open position of valve 24 and closed position. This long loading time is not good governor performance.

In my governor the centrifugal force is opposed by vacuum to prevent plastering of the governor throttle valve, which would cause sinking of the engine speed far below the governed speed, and surging. The vacuum is also opposed by centrifugal force. Consequently the two forces opposing each other and properly balanced against each other causes valve 24 to be very sensitive to speed changes of the engine. Naturally the metering of the air bleed through orifice 22 is in direct relation toVY engine speed, therefore at the slightest decrease in engine speed due tc load being applied the suction device will start to air bleed causing valve 4 to move towards an open position to admitl more charge increasing the power of the engine immediately when the slightest load is applied.

By actual test the governor valve will move from a closed position to a wide open position if the speed of the engine is reduced only 75 or 100 revolutions due to a l-oad being applied. This means very little change in vehicle or engine speed when the loads are being applied or released.

I realize it is not new to admit vacuum to a suction device by electrical or centrifugal speed means to control the speed of an engine, but in other devices the balance of the centrifugal force and vacuum against each other was never taken into consideration. Furthermore, in the other devices the flow of charge by the oriiices to start the governor valve towards a closed position was not taken into consideration. If it were, the orices would have been located in a position so that the charge would have the greatest effect, instead `of being located at random in the manifold and at a point where only the manifold vacuum (due to the governor valve closing) was relied on to power the suction device. In my device I rely both on the velocity to start the valve closed and the vacuum created by the valve moving towards a closed position to operate the governor throttle. Even though orifice I5 was not used, orifice I6 still should be located at a point where all of the charge passed it to create sufficient suction to start the governor valve towards a closed position. If orifice I6 was located at random in the engine manifoldwhere the charge for only part of the cylinders passed it, the suction would be so low that the valve would not start closed until the engine was far above the governor cut-oir speed or a speed at which the centrifugal device cl-osed the air bleed.

When the valve is wide open, projection 26 meters the air flowing through orice 22 to bleed d ovvn the vacuum in suction chamber 9. As the valve moves toward closed position the conical valve portion 2 cooperates with the conical valve seat 255 to meter the air flow into passageway I9 and conduits I2 and I3 to the suction chamber. Naturally as conical valve portion 2l moves to the right, the clearance between conical portion 21 and valve seatl 28 increases and the pressure in chamber 32 rises which in turn increases the air iiow through restricted passageways 30 and increases the pressure, that is, lowers the vacuum in back of piston 2lil in space 3|. Projection 26 is important because it assists materially in preventing iiuttering of valve 24 as it tends to close or momentarily closes orice 22.

This application is a continuation-impart of my prior application Serial No. 466,961, filed November 25, 1942, now Patent Number 2,381,550.

I claim:

1. In a speed governor for an internal combustion engine comprising an intake passageway, a governor throttle valve in the passageway and a suction device communicating with and responsive to changes in pressure in the intake passageway on the engine side of the governor valve and connected to the governor throttle valve for imparting movement thereto, the combination of iluid bleed mechanism for said suction device comprising a cylinder rotatable in accordance with the engine speed, a conduit communi eating with said cylinder and said suction device, a uid bleed orice in said cylinder, a centrifugally unbalanced piston valve reciprocable in said cylinder between said orifice and the said conduit, a restrictive by-passageway between portions of the cylinder in front and in rear of said valve, said ley-passageway restricting fluid ow whereby when the valve approaches closed position a lower` pressure exists in the portion of the cylinder on the suction side of said piston than in the portion of the cylinder between the piston and the iiuid bleed orifice, said centrifugal valve tending to close due to centrifugal force as the engine reaches its governed speed and in opposition to the suction in the intake passageway on the engine side of said governor valve, the piston valve body having a substantially greater cross sectional area than the fluid bleed orice, said valve having a conical valve portion and a cylindrical projection axially aligned on the front end of said piston valve, a cooperating conical valve seat surrounding the fluid bleed orice, the cylin- 6 drical projection projecting at all times into the orice to restrict iiuid iiow therethrough and the conical valve portion cooperating with the conical valve seat to control fluid flow through the air bleed orifice.

2. In a speed governor for an internal combustion engine wherein a throttle valve is controlled by a suction device which responds to changes in the intake passageway pressure on the engine side of the throttle valve, an air bleed mechanism for said suction device comprising a cylinder rotated in accordance with engine speed about an axis extending transversely to the longitudinal axis of the cylinder, a conduit connecting one end of the cylinder with the suction device, an air bleed oriiice in the other end of said cylinder, a piston in the cylinder having a body portion with a substantially greater cross sectional area than that of the air bleed orice, a conical seat around said orifice, a conical valve carried by said piston and arranged to co-act with said conical valve seat to control the air flow through said orifice, a bypassageway between the portion of the cylinder in front of the piston and the portion of the cylinder in back of the piston, said by-passageway restricting fluid flow around said piston whereby as the valve restricts air ilow through said orice the intake passageway suction acts on said piston valve body to oppose closing of the same, a cylindrical projection having a smaller cross sectional area than that of the orice and axially aligned with said conical valve and arranged to project into the orifice to restrict fluid air flow therethrough.

MARION MALLORY.

REFERENCES CITED The following references are of record in the file of this patent:

pNITED STATES PATENTS Number Name Date 2,224,600 Howard Dec. 10, 1940 2,322,764 Mallory June 29, 1943 2,381,550 Mallory Aug. 7, 1945 

